Department of Neurosurgery, The First Affiliated Hospital of PLA General Hospital, Beijing, China.
Brain Res. 2010 Aug 6;1347:104-10. doi: 10.1016/j.brainres.2010.05.029. Epub 2010 Jun 26.
CIRP (cold-inducible RNA-binding protein) mRNA is highly expressed in hypothermic conditions in mammalian cells, and the relationship between CIRP and neuroprotection for cerebral ischemia under hypothermia has been focused upon. At present, however, the expression characteristics of CIRP under hypothermia and cerebral ischemia in vivo are not clearly elucidated. In this study, CIRP mRNA expression in various regions of rat brain was examined by reverse transcriptase polymerase chain reaction (RT-PCR). CIRP expression levels were found to be similar in the hippocampus and cortex. Real-time quantitative PCR analysis revealed increasing CIRP mRNA expression in the cortex during the 24-h observation period following treatment with hypothermia or cerebral ischemia, with a greater increase in the hypothermia group. When cerebral ischemia was induced following hypothermia, CIRP mRNA expression in the cortex again showed a significant increasing tendency, but ischemia delayed the appearance of this increase. To reveal the relationship between CIRP and energy metabolism in the rat brain, lactate and pyruvate concentrations in the cortex of the rats treated with hypothermia, ischemia and ischemia after hypothermia were determined by spectrophotometric assay, and levels of phosphofructokinas-1 (PFK-1), the major regulatory enzyme of the glycolytic pathway, in the rat cortex in the three groups was also analyzed by Western blot. Using linear correlation, lactate and pyruvate concentrations, and PFK-1 levels, were each analyzed in the three groups in association with CIRP mRNA expression levels. The analysis did not reveal any correlation between the three metabolic parameters and CIRP mRNA expression induced by hypothermia, suggesting that while playing a role in neuroprotection under hypothermia, CIRP does not affect cerebral energy metabolism.
CIRP（冷诱导 RNA 结合蛋白）mRNA 在哺乳动物细胞的低温条件下高度表达，并且已经关注了 CIRP 与低温下脑缺血的神经保护之间的关系。然而，目前尚不清楚 CIRP 在体内低温和脑缺血下的表达特征。在这项研究中，通过逆转录聚合酶链反应（RT-PCR）检查了大鼠脑的各个区域中的 CIRP mRNA 表达。发现 CIRP 表达水平在海马体和皮质中相似。实时定量 PCR 分析显示，在低温或脑缺血处理后 24 小时观察期间，皮质中的 CIRP mRNA 表达增加，低温组增加更大。当在低温后诱导脑缺血时，皮质中的 CIRP mRNA 表达再次显示出明显的增加趋势，但缺血延迟了这种增加的出现。为了揭示 CIRP 与大鼠脑内能量代谢之间的关系，通过分光光度法测定了接受低温、缺血和低温后缺血处理的大鼠皮质中的乳酸和丙酮酸浓度，并通过 Western blot 分析了三组大鼠皮质中的磷酸果糖激酶-1（PFK-1）的水平，PFK-1 是糖酵解途径的主要调节酶。通过线性相关，在三组中分别分析了乳酸和丙酮酸浓度以及 PFK-1 水平与 CIRP mRNA 表达水平的关系。分析未显示出三种代谢参数与低温诱导的 CIRP mRNA 表达之间的任何相关性，这表明尽管在低温下发挥神经保护作用，但 CIRP 不影响脑能量代谢。
